Transillumination catheter and system

ABSTRACT

A method of identifying vasculature comprising the steps of introducing an indicator in a peripheral vessel, and advancing a portion of the indicator into an internal vessel to identify said vessel. A catheter for identifying vasculature is also disclosed. The catheter is adapted to be introduced into a peripheral vessel and a portion thereof advanced into an internal vessel. The catheter comprises a light delivery portion at a distal end thereof and an expandable member located proximal to the light delivery portion.

FIELD OF THE INVENTION

[0001] The present invention relates generally to methods and devicesfor facilitating surgical procedures, and more particularly to methodsand devices for transilluminating an internal blood vessel, artery orvein within a patient during a cardiac surgery procedure to facilitatelocating and manipulating the vessel, artery or vein.

BACKGROUND OF THE INVENTION

[0002] Minimally invasive surgical techniques have revolutionizedcardiac surgery. Minimally invasive cardiac surgery enjoys theadvantages of reduced morbidity, quicker recovery times, and improvedcosmesis over conventional open-chest cardiac surgery. Recent advancesin endoscopic instruments and percutaneous access to a patient'sthoracic cavity have made minimally invasive surgery possible. Reductionin morbidity, lower cost, and reduced trauma has made minimally invasivesurgery desirable.

[0003] However, many problems and controversies still surround theviability of minimally invasive cardiac surgical procedures. One suchproblem is the difficulties of locating and manipulating small vessels,arteries, or veins in a closed-chest, blind environment during, forexample, a minimally invasive coronary artery bypass graft (CABG)procedure. The coronary arteries typically have a diameter in the rangeof between about 1 to 5 mm, and the coronary bypass graft vessels have adiameter on the order of about 1 to 4 mm for an arterial graft such as athoracic artery 56, or about 4 to 8 mm for a vein graft such as asaphenous vein 84. Locating and manipulating these tiny vessels issufficiently difficult in conventional open-chest cardiac surgicalprocedures, and is made substantially more difficult in closed-chest,less invasive mini-thoracotomy procedures and in minimally invasiveendoscopic procedures where the cardiac surgeon may not be able to viewthese vessels directly. Endoscopic instruments are currently used by thecardiac surgeon to view the internal thoracic cavity during a minimallyinvasive surgical procedure, but the use of these instruments alone hasinherent drawbacks. For example, it is often difficult to differentiatethe often tiny coronary arteries or coronary bypass graft vessels fromother surrounding vessels and tissues with the use of endoscopicinstruments alone during a minimally invasive surgical procedure.

[0004] An alternative technique for performing minimally invasivecardiac surgery procedures, therefore, is needed which facilitateslocating and manipulating vessels by illumination from within thevessels. The technique should employ transillumination of a coronaryvessel or coronary bypass graft vessel with light at predeterminedwavelengths that are not substantially absorbed by the vessel itself,blood, other bodily fluids, or surrounding tissues and the like. Thesurgical technique can be applied for example, to the following areas,although it is to be understood that the present invention is by nomeans limited to these specific cardiac surgery procedures: (1)dissecting a left (or right) internal thoracic artery (LITA or RITA)from the chest wall in preparation for anastomosing the LITA to a nativecoronary vessel in a CABG procedure; (2) locating the LITA graft in aCABG repeat procedure; (3) locating the coronary artery to which acoronary bypass graft vessel is to be anastomosed; and (4) harvesting afree graft vessel, such as a saphenous vein, in preparation foranastomosing the free graft vessel to a native coronary artery in a CABGprocedure. Each of these procedures will be explained in greater detailhereinafter.

[0005] Transillumination within the body of a patient has beenrecognized for at least a century. As long ago as the mid-1800's,British physicians began detecting scrotal cancer by holding a lampbehind the testes and noting the shadows the tumors cast. See“Transillumination: Looking Right Through You,” Science, Vol. 261, Jul.30, 1993 at page 560. Transillumination of the stomach was reported asearly as 1911. Intraoperative transillumination of the small intestineand colon also is generally well known. See, e.g., Ambartsoumian, A.,“Infrared Transillumination Gastroscopy,” Gastrointestinal Endoscopy1995:41(3):270-71. Illuminators for transilluminating internal organs orvessels have been used in the fields of urology and gastroentology. Anilluminator placed in the urethra or esophagus facilitates laproscopicand cystoscopic procedures by illuminating these organs thus avoidingunwanted damage to the organs. See, e.g., U.S. Pat. No. 5,624,432 toAngelchik (describing the preferred use of an illuminated bougie forilluminating the esophagus). Transillumination has also been used tofacilitate the proper intracorporeal placement of catheters. See, e.g.,U.S. Pat. No. 5,370,640 to Kolff, which discloses the use of afiberoptic stylet device for facilitating the intracorpoeal placement ofa retrograde coronary sinus catheter into the coronary sinus of a heartof a patient.

[0006] Although illuminators are generally well known by those skilledin the art, they typically have application for diagnostic ortherapeutic purposes. Examples of such devices include the illuminatorsdisclosed in U.S. Pat. No. 5,169,395 to Narciso, Jr., U.S Pat. No.5,196,005 to Doiron et al., U.S Pat. No. 5,269,777 to Doiron et al., U.SPat. No. 5,330,465 to Doiron et al., U.S Pat. No. 5,441,497 to NarcisoJr., and U.S Pat. No. 5,454,794 to Narciso, Jr. et al. The devicesdescribed in those patents generally have the ability to deliver lightto luminal surfaces such as blood vessels and are typically used for thediagnosis and treatment of a variety of medical conditions, withparticular application to performing photodynamic therapy (PDT) in thetreatment of diseased tissue such as tumors, inducing hyperthermia, orperforming both percutaneous and intraoperative phototherapy ofcardiovascular disease. However, despite the fact that transilluminationhas long been known, the present invention is believed to be the firstuse of transillumination to facilitate CABG surgery by any one of themethods described below.

SUMMARY OF THE INVENTION

[0007] The present invention discloses methods and devices foridentifying vasculature. The identification methods and devicesdescribed herein can be used in conjunction with a combined techniqueinvolving laparoscopy and endoscopy to facilitate viewing andmanipulating internal vessels during CABG and other cardiac surgeryprocedures. The techniques of the present invention can be used inopen-chest coronary surgery where a partial or median sternotomy is usedto gain access to the heart, in closed-chest less invasive coronarysurgery procedures where a mini-thoracotomy is used to gain access tothe heart, or in totally endoscopic procedures where a series of smallholes, or ports, in the chest wall are used to gain access to the heart.

[0008] A method of the present invention is for identifying vasculatureand generally comprises the steps of introducing an indicator in aperipheral vessel and advancing a portion of the indicator into aninternal vessel to identify the vessel.

[0009] In another aspect of the invention, a catheter for identifyingvasculature is adapted to be introduced into a peripheral vessel and aportion thereof advanced into an internal vessel. The catheter generallycomprises a light delivery portion at a distal end thereof, and anexpandable member located proximal to the light delivery portion.

[0010] In yet another aspect of the invention, a system for deliveringenergy to an internal vessel of a patient generally comprises a catheterand a catheter guide. The catheter comprises a flexible, elongated shafthaving a proximal end, a distal end, and an energy transmitting diffuserlocated at the distal end of the shaft. The catheter guide has anopening which is sized and dimensioned to permit the catheter to beinserted longitudinally within the guide. The guide is configured forintroduction into the peripheral vessel and advancement to the internalvessel to facilitate delivery of the catheter into the internal vessel.

[0011] Additional features and advantages of the invention will be setforth in or are apparent from the detailed descriptions of the preferredembodiments found herein below.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012]FIG. 1 is a schematic illustration of the transilluminationcatheter of the present invention.

[0013]FIG. 2 is a longitudinal cross-sectional view of a distal end ofthe transillumination catheter of FIG. 1.

[0014]FIG. 3 schematically illustrates insertion of thetransillumination catheter into a brachial artery 48 of a patient foradvancement to a left internal thoracic artery 56 via a left subclavianartery 90.

[0015]FIG. 4 is an enlarged view of a patient's heart schematicallyshowing the transillumination catheter disposed within a subclavianartery and being advanced towards the left internal thoracic artery.

[0016]FIG. 5 is an enlarged view of a patient's heart schematicallyshowing the transillumination catheter disposed within a subclavianartery and being advanced towards the left internal thoracic artery in arepeat CABG procedure.

[0017]FIG. 6 is an enlarged view of a patient's heart schematicallyshowing the transillumination catheter disposed within a stenoticcoronary artery.

[0018]FIG. 7 schematically illustrates insertion of thetransillumination catheter of FIG. 1 into a saphenous vein of a patientfor illumination of the vein prior to harvesting it for a coronaryanastomosis procedure, along with showing other vessels which can beilluminated.

[0019]FIG. 8 is a schematic diagram of an alternative embodiment of thetransillumination catheter of FIG. 1.

[0020]FIG. 9 shows the transilluminator catheter device of FIG. 8positioned within a LITA graft vessel which has an anastomotic fastenerpositioned about an external surface of a free end portion of the graftvessel.

[0021]FIG. 10 shows the free end portion of the graft vessel evertedover a portion of the anastomotic fastener.

[0022]FIG. 11 shows the graft vessel with the transillumination catheterof FIG. 8 positioned therein being inserted into the target vesselthrough an incision in the target vessel.

[0023]FIG. 12 is an elevated view of the anastomotic fastener followinglight irradiation and radial expansion of a balloon of thetransillumination catheter.

[0024]FIG. 13 is an elevated view of the anastomotic fastener after thetransillumination catheter has been removed from the graft vesselshowing the completed anastomosis.

[0025]FIG. 14 is a schematic diagram of an alternative embodiment of thetransillumination catheter of FIG. 1.

[0026]FIG. 15 is a schematic illustration of a catheter guide and guidewire for facilitating placement of the transillumination catheter intoan internal vessel.

DESCRIPTION OF THE INVENTION

[0027] Referring now to the drawings, and first to FIG. 1, an indicatorfor identifying vasculature is shown and is generally indicated by thereference numeral 10. The indicator 10 of the present invention isuseful for delivering energy, such as visible, infrared, or ultravioletlight energy, to within a vessel, artery or vein during a coronarysurgery procedure, such as a CABG procedure, to illuminate the vessel,artery or vein. Such transillumination of an internal vessel facilitateslocating and manipulating the vessel during the surgical procedure. Theindicator 10 can be used to facilitate open-chest coronary surgeryprocedures, closed-chest less invasive mini-thoracotomy surgeryprocedures, and totally endoscopic minimally invasive procedures.

[0028] The indicator 10 comprises a transillumination catheter having alight delivery portion for transmitting light to identify a vessel. Thelight is preferably diffused over a section of the distal end of thecatheter 10 to sufficiently illuminate the vessel. The catheter 10includes a fiber optic connector 23 at a proximal end of the catheterwhich is in optical communication with an energy source (not shown),such as a laser or a broad-band light source. In the latter case, awavelength of between about 400 and 700 nm, and more preferably betweenabout 600 and 700 nm, is preferred since this range of wavelengths willfacilitate the emitted light energy to pass through bodily tissue. Thefiber optic connector 23 can also be optically connected to anultraviolet or infrared light energy source. Ultraviolet light typicallyhas a wavelength of between about 100 and 400 nmn and infrared lighttypically has a wavelength of between about 700 and 15,000 nm. The lightfrom the light is delivered to a single optical fiber or bundle ofoptical fibers 25 enclosed within a first, inner catheter sheath 21. Theoptical fiber or bundle of optical fibers 25 is contained within andextends the length of the catheter 10 from the fiber optic connector 23to the distal portion of the catheter 10 proximal to the light diffusingend member 14 of the catheter.

[0029] The catheter 10 includes a Y-shaped adapter 20 towards itsmid-portion which is in fluid communication with an opaque, outercatheter sheath 18 which terminates at the proximal face of lightdiffusing end member 14. Inner catheter sheath 18 is sufficientlyflexible to navigate tortuous vessels without great difficulty, and ispreferably made from one or more biocompatible thermoplastic materialswhich have the optical and thermal properties required for this deviceto be operable such as Teflon®, polyurethane, polyethylene, polyethyleneterephthalate, or other suitable biocompatible materials or combinationsthereof.

[0030] The Y-shaped adapter 20 includes a balloon inflation/deflationport 22 through which a fluid may be administered and fluidlycommunicated through an inflation/deflation channel 30 (see FIG. 2)created between the external sheath 18 and inner sheath 21 to theballoon 16. The distal end of the transillumination catheter 10 includesa light diffusing end member 14 which is optically coupled to the distalface of optical fiber 25. The light diffusing end member 14 is marked bya pair of radiopaque markers 13 for visualization of the catheter 10under x-ray fluoroscopy. Radiopaque markers 13 can be fabricated fromgold, platinum, platinum-iridium, or any one of a number of otherrelatively dense materials. The distal portion of the catheter 10 iscurved as shown to provide steering capabilities through a vessel whichobviates the need for a distal guidewire or an internal steering wire orother steering mechanism. The shape of the distal portion of thecatheter can be set thermally during processing or an additional coil(not shown) can be placed into the distal portion of catheter 10 as iswell known by a person of ordinary skill in the art.

[0031] The transillumination catheter 10 is preferably dimensioned andconfigured for introduction into a peripheral vessel, such as a brachialor radial artery 51 of a patient, and advanced to an internal thoracicartery of the heart (i.e., the LITA) through a subclavian artery (i.e.,the left subclavian artery 90). This will generally require a catheterlength of between about 20 to 60 cm. In addition, the catheter 10 may beconfigured to be inserted directly into a vein graft, such as asapahenous vein, for illuminating the vein graft, in which case thecatheter 10 will have a similar length of between about 20 to 60 cm.Alternatively, the catheter 10 may be adapted for introduction into afemoral artery 82 and advancement to a coronary or other vessel, such asan internal thoracic artery for example, wherein the catheter will needto be longer in length, for example about 90 to 120 cm. The catheter 10may be adapted for introduction into several coronary arteries and othervessels, such as a right coronary artery 60, a left main coronary artery58, a left anterior descending artery 64, a left circumflex 62, an aorta56, a proximal coronary artery, including any branches thereof, from thesame or other peripheral vessels such as a radial artery 51, leftcarotid artery 52, right carotid artery 54, brachial artery 48,subclavian artery 90, or femoral artery 82, in which case its lengthwill vary depending on the particular vessel and route of administrationchosen. (See FIGS. 3-7).

[0032] Referring now to FIG. 2, a longitudinal cross-sectional view ofthe distal end of the transillumination catheter 10 is shown. As seen inFIG. 2, optical fiber (or bundle of optical fibers) 25 iscircumferentially surrounded by cladding 27 which promotes completeinternal reflection of the light transmitted down the core of opticalfiber 25. The distal portion of the cladding 27 is surrounded by anoptical fiber centering sleeve 29. The light is transmitted from thedistal face of optical fiber 25 to the light diffusing medium 15 encasedwithin light diffusing end member 14. Light diffusing medium 15 isfabricated from an optically clear substrate such as silicone withoptical scattering centers distributed within the substrate. The opticalscattering centers can be fabricated from alumina, silica, titaniumoxide, calcium carbonate, or other suitable materials. By varying theconcentration of scattering centers in the light diffusing medium 15from lowest at the optical fiber 25 to greatest at the rounded cap 12,as shown, either discretely or continuously, the light outputdistribution from the light diffusing end member 14 can be made bothradially and axially uniform. Alternatively, the optical scatteringcenters can be uniformly distributed throughout light diffusing medium15.

[0033] The transillumination catheter 10 shown in FIGS. 1-2 can be usedin any one of several novel ways to facilitate locating and manipulatingvessels, arteries or veins in coronary surgery procedures. FIG. 4 showsone such novel use of transillumination catheter 10 for locating andilluminating a LITA graft vessel 46 prior to dissecting the LITA graftfrom the chest wall in preparation for a CABG procedure. The LITAtransillumination technique can be used in open-chest coronary surgerywhere a partial or median sternotomy is used to gain access to the heartor in closed-chest less invasive coronary surgery procedures where amini-thoracotomy is used to gain access to the heart The harvest of theLITA 46 (or RITA 45) for coronary bypass grafting can also be performedthoracoscopically through three small skin incisions as fully describedin Duhaylongsod, F.G. M.D., Mayfield, W.R. M.D., Wolf, R.K. M.D.,“Thoracoscopic Harvest of the Internal Thoracic Artery for CoronaryBypass Grafting: A Multicenter Experience in 219 Cases,” presented atthe “Facts & Myths of Minimally Invasive Cardiac Surgery: Current Trendsin Thoracic Surgery IV” symposium before the 34^(th) Annual Meeting ofthe Society of Thoracic Surgeons, New Orleans, LA, Jan. 24, 1998, theentire contents of which are incorporated by reference herein. Thefollowing is an exemplary usage of the LITA transillumination techniquein a standard mini-thoracotomy procedure.

[0034] A transillumination catheter, such as catheter 10 in FIGS. 1-2,is first percutaneously inserted into a peripheral vessel, such as abrachial artery 48, by conventional means and advanced with the aid ofx-ray fluoroscopy into the LITA 46 via a subclavian artery to provideillumination of the LITA, as schematically illustrated in FIGS. 3-4. Asnoted above, the catheter 10 can also be percutaneously inserted intoother peripheral vessels as well, such as a radial artery 51 or afemoral artery 82, by a suitable technique, such as the Seldingertechnique, and advanced through a subclavian artery into the LITA (orother coronary vessel). Applicants have demonstrated that the use of atransillumination catheter placed within the LITA helps to facilitatethe procedure of locating, manipulating and dissecting the LITA from thechest wall without damage or unnecessary morbidity to the surroundingtissues and body structures.

[0035] After establishment of general anesthesia with a double-lumenendobronchial tube, for example, allowing complete collapse of the leftor right lung, the left lung is deflated to allow access to the heartand LITA. A 6 to 8 cm left anterior thoracotomy incision is then made inthe patient's chest in the fourth intercostal space. Other sites may besuitable depending on the patient's anatomy, such as the fifth or sixthintercostal space. A retractor is used to spread apart the ribs toprovide access to the heart and the LITA. The LITA is then dissectedunder direct vision with suitable instruments introduced through thethoractomy incision, such as scissors, pliers and the like. The balloon16 of catheter 10 is used to internally seal the LITA graft vessel priorto transecting the distal end of the LITA graft in preparation for thecoronary anastomosis procedure. This obviates the need for usingexternal clamps to provide hemostasis within the graft vessel prior totransection. Following dissection of the LITA, the resulting LITApedicle is transected with a suitable instrument such as scissorsthrough the thoracotomy. Papaverine is then injected directly throughthe LITA, which is prepared for coronary anastomosis to a stenoticcoronary artery 64. The anastomosis of the LITA to the coronary arteryis then performed directly through the thoracotomy incision by usingconventional suturing means, or by using a novel distal anastomosisdevice and procedure such as described below in connection with FIGS.8-13 and in co-pending patent application for Anastomosis Device andMethod, filed on Mar. 9, 1998, and invented by Hugh Narciso, Jr.

[0036] If required, cardiac stabilization such as described inco-pending provisional patent application, Ser. No. 60/055,127, forCompositions, Apparatus and Methods for Facilitating SurgicalProcedures, filed Aug. 8, 1997, and invented by Francis G. Duhaylongsod,M.D., may be used during the procedure. Other pharmacological ormechanical methods may also be used.

[0037] A second preferred intended novel use of the present invention isfor locating the LITA, for example, in a repeat coronary surgicalprocedure, such as in a redo CABG procedure, to prevent injury whileattempting to correct an imperfect anastomosis graft between the LITAand a stenotic native coronary artery, such as the LAD. As noted above,locating the LITA during repeat CABO surgery, for example, is criticalto the safety of the patient because the graft LITA represents one ofthe major supplies of blood to the heart. When the LITA is anastomosedto the LAD, for example, it typically is placed across the anteriorsurface of the heart, directly under the sternum, as shown in FIG. 5. Ifa second, or redo, CABG procedure needs to be performed, the cardiacsurgeon typically needs to bisect the sternum to gain access to theheart. Often in doing so, the surgeon inadvertently compromises the LITAgraft 70 and the patient has limited alternatives if the LITA graftcannot be repaired.

[0038] To alleviate this concern, as described above, atransillumination catheter, such as catheter 10 in FIGS. 1-2, ispercutaneously inserted into a peripheral vessel, such as a brachialartery 48 or radial artery 51, and advanced into the LITA 46 via asubclavian artery 40 to provide illumination of the LITA, asschematically illustrated in FIG. 5. We have demonstrated that lightdiffusing from a transillumination catheter at a specific wavelength orwavelengths (for example, at a wavelength of between about 400 and 700nm, and more preferably between about 600 and 700 nm) which is placedwithin the lumen of the LITA graft vessel is completely visible throughthe chest wall of the patient. With a transilluminator catheter in placeand the LITA graft 46 illuminated, using current techniques, a surgeoncan accurately perform a partial or median sternotomy to gain accessinto the patient's thoracic cavity while avoiding the illuminated LITAgraft vessel, thus obviating difficulties associated with a compromisedLITA graft 46. A partial or median sternotomy is a procedure by which asaw or other appropriate cutting instrument is used to make a midline,longitudinal incision along a portion or the entire axial length of thepatient's sternum, allowing two opposing sternal halves to be separatedlaterally. A large opening into the thoracic cavity is thus created,through which a surgeon may directly visualize and operate upon theheart to correct the imperfect anastomosis or diseased graft vessel.

[0039] Another preferred intended novel use for the present invention isfor locating and manipulating stenotic coronary vessels to which a graftvessel is being anastomosed in a CABG procedure. When performing CABGsurgery, the stenotic native coronary artery to which a graft vessel isbeing anastomosed is obscured by surrounding fat or cardiac tissues. Thecardiac surgeon must cut through tissues to access the coronary arteryfor purposes of creating a clear field of view to perform theanastomosis procedure. In some instances, it is possible for the cardiacsurgeon to compromise the stenotic coronary artery 64 while attemptingto cut through the fat and cardiac tissues. However, with atransilluminator catheter in place within the coronary artery, thecardiac surgeon will be able to dissect the surrounding tissues from thecoronary artery thus exposing the artery for the anastomosis procedure.In this preferred use of catheter 10, the catheter 10 is percutaneosulyinserted into a peripheral vessel, such as a brachial or radial artery51, as schematically illustrated in FIG. 6. Illumination of thetransillumination catheter 10 will help the surgeon to visualize thestenotic coronary artery 64 while the graft vessel, such as the LITApedicle 46 shown in FIG. 6, is being anastomosed to it.

[0040]FIG. 7 schematically illustrates another preferred novel use ofthe transillumination catheter 10 of the present invention forharvesting a free vessel graft, typically a saphenous vein 84, from apatient undergoing a CABG procedure. FIG. 7 illustrates the location ofvarious vessels, including the abdominal aorta 74, the common iliacartery 76 and the femoral vein 80. A transilluminator catheter 10 ispercutaneously inserted under the skin and inserted into a saphenousvein 84. With the transilluminator in place and the saphenous vein 84illuminated, a surgeon gently dissects the saphenous vein 84 withsuitable surgical instruments, such as scissors and the like. The devicemay be used to transilluminate other bypass graft vessels such as agastroepiploic artery 72 or an inferior epigastric artery 78. The use ofa transillumination device placed within the vein to be harvested makesthe harvesting procedure simpler and facilitates location and extractionof the graft vessel. The transillumination catheter can be used incombination with conventional endoscopic techniques to simplify theprocess of harvesting the vein graft in an endoscopic procedure.

[0041]FIG. 8 illustrates an alternative embodiment of thetransillumination catheter 10 of FIGS. 1-2 generally indicated byreference numeral 100, wherein like numerals represent like parts. Forexample, the optical fiber 25, fiber optic connector 23, catheter sheath21, and light diffusing end member 14 have the same general function andarrangement as described in FIGS. 1-2. Transillumination catheter 100can be used to facilitate the coronary surgical procedures describedabove akin to catheter 10, and can also be used to facilitate joining atransected graft vessel to a stenotic target vessel in a coronaryanastomosis, as will be described in greater detail below.

[0042] As shown in FIG. 8, the Y-adapter 20 of catheter 10 is replacedwith a three arm adapter 40 which incorporates two separate andindependent balloon inflation/deflation ports 42, 44 which allow theaddition of fluid, such as saline, through an inflation/deflationchannel (not shown) defined by outer sheath 18′ to the distal balloons16′ and 50, respectively. Balloon 50 is affixed to the outer sheath 18′so that the balloon 50 overlies a substantial portion of the lightdiffusing end member 14 of catheter 100. The wall of the balloon 50 istransparent at the wavelength of light being delivered to (or receivedfrom) the surrounding tissue from light diffusing end member 14. Distaland proximal to balloon 50 are radiopaque marker bands 13′ forvisualization under x-ray fluoroscopy. The provision of a second balloon50 is advantageous where the transillumination catheter 100 of thepresent invention is used in connection with a novel distal anastomosisdevice disclosed in co-pending patent application for “AnastomosisDevice and Method,” filed on Mar. 9, 1998, and sharing a common inventor(Hugh L. Narciso, Jr.), the entire contents of which are fullyincorporated by reference herein.

[0043] As described therein, an anastomotic fastener is disclosed whichin one embodiment comprises a tubular sleeve formed of a deformablematerial, such as a light-activated polymeric material (i.e., apolycaprolactone material) which becomes formable (i.e., fluent) uponthe application of light energy to the material at a specific frequency,wavelength or wavelengths. The anastomotic fastener is configured to bepositioned radially adjacent a free end portion of a graft vessel, suchas a LITA graft, which is then preferably everted over a portion of thetubular sleeve. The deformable material may be selectively irradiatedand molded in vivo by providing an energy that produces radiation at afrequency, wavelength, or wavelengths that are readily absorbed by thematerial. Radial expansion of the graft vessel will permit thedeformable material in its moldable state to be shaped such that thefree end portion of the graft vessel in its everted configuration is insecure conforming engagement with an inner wall of the target vessel,resulting in an intima-to-intima anastomosis. Transillumination catheter100 can be used in lieu of the light-diffusing catheter described in thesubject co-pending patent application to irradiate and radially expandthe anastomotic fastener device.

[0044] For example, with reference to FIGS. 9-13, transilluminationcatheter 100 is first inserted into a LITA graft vessel 110 in a similarfashion as described above in connection with FIGS. 3-4, and the LITAgraft vessel 110 can be illuminated and then dissected and transectedusing balloon 16′ to seal the LITA prior to transecting it. With a freeend portion of the LITA graft vessel 110 exposed as shown in FIG. 9 andballoon 16 expanded to occlude the vessel, a deformable anastomosisfastener device 120 can be positioned about an external surface of (orinserted into) a free end portion of the LITA graft 110, whichpreferably is then everted over a portion of the tubular sleeve 120 (seeFIGS. 9-10). The LITA graft vessel 110 is then inserted into a targetvessel 112, such as an LAD having a stenotic region 113, through anincision in a wall of the target vessel 112.

[0045] With the anastomotic fastener 120 securely positioned in thetarget vessel 112, light energy at a given wavelength or wavelengths issupplied to the light diffusing end member 14 of catheter 100 from theenergy (not shown) via optical fiber 25 to irradiate, or illuminate, thetubular member 120 with light at a wavelength or wavelengths at whichthe deformable material readily absorbs. Upon absorption of the lightenergy, the deformable material forming tubular member 120 istransformed into its moldable, fluent state. Inflation of the balloon 50causes the tubular member 120 to radially expand outwardly, therebypressing the LITA graft vessel 110 into conforming engagement with aninner wall of target vessel 112 (see FIG. 12). If it is necessary tomove catheter 100 longitudinally within the graft vessel 110 to, forexample, precisely position balloon 50 radially adjacent tubular member120, balloon 16′ can be deflated slightly. This will permit longitudinalmovement of the catheter 100 within the graft vessel 110, at which pointballoon 16′ can then be re-inflated fully to firmly seal the graftvessel 110 and prevent blood flow into the anastomosis site. Bydiscontinuing the supply of light energy from the energy, the deformablematerial will become non-fluent and remain in its molded configuration.Both balloons 16′, 50 are then deflated and the catheter device 100 iswithdrawn from the LITA graft vessel 110 to complete the anastomosis(see FIG. 13).

[0046]FIG. 14 is a third alternative embodiment of a transilluminationcatheter generally indicated by reference numeral 200. Thetransillumination catheter 200 is similar in most respects to thetransillumination catheter 10 of FIGS. 1-2, except that the distal endof the catheter 200 is substantially straight, and does not have acurved configuration as does the distal end of catheter 10. A catheterguide 205 is shown in schematic form in FIG. 15. The guide 205 comprisesa flexible, elongate tubular body 210 which is sized and dimensioned topermit catheter 200 to be longitudinally inserted within the tubularbody 210. Tubular body 210 may be manufactured from any suitable,relatively flexible biocompatible plastic such as polyethylene,polyurethane, silicone, and the like. The guide 205 facilitatesplacement of transillumination catheter 200 within an internal vessel,such as a LITA graft vessel. The catheter 200 may be formed with a guidewire lumen (not shown) as described in U.S. Pat. No. 5,169,395, which isincorporated herein by reference. The lumen may be used for insertion ofa guidewire or insertion of a fluoroscopic dye to assist in guiding thecatheter.

[0047] In use of the above system, the guide 205 is first percutaneouslyinserted into a peripheral vessel, such as a brachial artery 48, radialartery 51 or femoral artery 82, and advanced over a guidewire 220 byconventional means to an internal vessel, such as LITA graft vessel.With the distal end of tubular body 210 positioned a short distancewithin the internal vessel, the guidewire 220 is pulled back and removedfrom tubular body 210. Subsequently, transillumination catheter 200 canbe longitudinally inserted into tubular body 210 and advancedtransluminally through it such that the light transmitting diffusing endmember 14′ is placed within the internal vessel and extends beyond thedistal end of the tubular body 210. Alternatively, tubular body 210 maybe advanced into the internal vessel to a position at whichtransillumination of the vessel is required. Subsequently, the distalend of transillumination catheter 200 is advanced up to the distal endof tubular body 210, and the tubular body 210 is then pulled back ashort distance over the transillumination catheter 200 to expose thelight transmitting distal end member 14′ of the catheter 200. Thetransillumination catheter 200 is then used to illuminate the internalvessel as described above. The guide 205 is advantageous in that it canbe used to effectively guide catheter 200 into an internal vessel,obviating the need to shape the distal end of catheter 200 or to providea guidewire or other steering mechanism within catheter 200.

[0048] It should be understood that while the above is a completedescription of the preferred embodiments of the invention, variousalternatives, modifications and equivalents may be used. Therefore, theabove description should not be taken as limiting the scope of theinvention which is defined by the following claims.

What is claimed is:
 1. A method of identifying vasculature comprisingthe steps of introducing an indicator in a peripheral vessel, andadvancing a portion of the indicator into an internal vessel to identifysaid vessel.
 2. The method of claim 1 wherein the step of introducing anindicator comprises introducing a catheter having a light deliveryportion, and further comprising the step of activating the lightdelivery portion to transmit light and identify the vessel.
 3. Themethod of claim 2 further including the step of diffusing thetransmitted light.
 4. The method of claim 3 wherein the light has awavelength in the range of 100 to 1100 nm.
 5. The method of claim 3wherein the light has a wavelength in the range of 400 to 700 nm.
 6. Themethod of claim 3 wherein the light has a wavelength in the range of 600to 700 nm.
 7. The method of claim 2 further comprising the step ofoccluding blood flow through the internal vessel.
 8. The method of claim7 wherein said catheter comprises a balloon and said step of occludingcomprises expanding the balloon.
 9. The method of claim 8 furthercomprising the step of transecting a distal end of said internal vesselin preparation for a coronary anastomosis after expanding the balloon.10. The method of claim 9 wherein said internal vessel is an internalthoracic artery and further comprising the step of sealingly joining afree end of said internal thoracic artery to a stenotic coronary arteryafter transecting the distal end of said internal thoracic artery. 11.The method of claim 1 wherein the internal vessel comprises an internalthoracic artery.
 12. The method of claim 1 wherein the internal vesselcomprises a right coronary artery.
 13. The method of claim 1 wherein theinternal vessel comprises a left main coronary artery.
 14. The method ofclaim 1 wherein the internal vessel comprises a left anterior descendingartery.
 15. The method of claim 1 wherein the internal vessel comprisesa left circumflex.
 16. The method of claim 1 wherein the internal vesselcomprises an aorta.
 17. The method of claim 1 wherein the internalvessel comprises any branches off of a proximal coronary artery.
 18. Themethod of claim 1 wherein the internal vessel comprises a bypass graftvessel.
 19. The method of claim 18 wherein the bypass graft vesselcomprises a gastroepiploic artery
 20. The method of claim 18 wherein thebypass graft vessel comprises an inferior epigastric artery.
 21. Themethod of claim 1 wherein the peripheral vessel comprises a brachialartery.
 22. The method of claim 1 wherein the peripheral vesselcomprises a radial artery.
 23. The method of claim 1 wherein theperipheral vessel comprises a femoral artery.
 24. The method of claim 1wherein the peripheral vessel comprises a carotid artery.
 25. The methodof claim 11 further comprising the step of dissecting at least a portionof the internal thoracic artery after advancing the indicator.
 26. Themethod of claim 11 further comprising the step of separating a sternumafter advancing the indicator.
 27. A method of identifying a saphenousvein for a surgical procedure comprising the steps of introducing atleast a portion of an indicator having a light delivery portion at adistal end thereof into the saphenous vein and transmitting lightthrough the light delivery portion to identify the vein.
 28. A catheterfor identifying vasculature, the catheter adapted to be introduced intoa peripheral vessel and a portion thereof advanced into an internalvessel, the catheter comprising a light delivery portion at a distal endthereof, and an expandable member located proximal to said lightdelivery portion.
 29. The catheter of claim 28 further comprising anoptical fiber.
 30. The catheter of claim 28 wherein said light deliveryportion is adapted to transmit energy having a wavelength in the rangeof 100 to 1100 nm.
 31. The catheter of claim 28 wherein said lightdelivery portion is adapted to transmit energy having a wavelength inthe range of 400 to 700 nm.
 32. The catheter of claim 28 wherein saidlight delivery portion is adapted to transmit energy having a wavelengthin the range of 600 to 700 nm.
 33. The catheter of claim 28 furthercomprising a second expandable member located distal to said firstexpandable member and surrounding a substantial portion of said lightdelivery portion.
 34. The catheter of claim 28 further comprising a bendin the distal end thereof to facilitate positioning the catheter in theinternal vessel.
 35. A method of performing a coronary artery bypassgraft procedure on a patient's heart comprising the steps of: forming atleast one opening in the patient's chest; locating a bypass graft vesselto provide an arterial blood supply; illuminating said bypass graftvessel; dissecting at least a portion of said bypass graft vessel;transecting a distal end portion of said bypass graft vessel; andconnecting said distal end portion of the bypass graft vessel to acoronary artery with said bypass graft vessel in fluid communicationwith said coronary artery.
 36. The method of claim 34 wherein saidilluminating step comprises inserting a catheter having a light deliveryportion into said bypass graft vessel.
 37. The method of claim 35wherein said light delivery portion is adapted to deliver light having awavelength in the range of 100 to 1100 nm.
 38. The method of claim 35wherein said light delivery portion is adapted to deliver light having awavelength in the range of 400 and 700 nm.
 39. The method of claim 35wherein said light delivery portion is adapted to deliver light having awavelength in the range of 600 to 700 nm.
 40. The method of claim 35wherein said catheter comprises a balloon and further comprising thestep of occluding said bypass graft vessel by inflating the balloonprior to said transecting step.
 41. A system for delivering energy to aninternal vessel of a patient comprising: a catheter comprising aflexible, elongated shaft having a proximal end, a distal end, and anenergy transmitting diffuser located at the distal end of the shaft; anda catheter guide having an opening which is sized and dimensioned topermit said catheter to be inserted longitudinally within said guide,said guide being configured for introduction into the peripheral vesseland advancement to said internal vessel to facilitate delivery of saidcatheter into said internal vessel.
 42. The system of claim 40 furthercomprising a guidewire adapted to extend through a longitudinal openingwithin the catheter guide.